Large vehicles, such as trucks and heavily instrumented transporters, require high energy alternators to supply the electrical requirements of such vehicles. Because of space considerations, such alternators are usually very compact and as result, they generate a considerable amount of heat that must be dissipated in order to prevent damage to the alternator.
Conventionally, cooling is achieved by constructing the housing of the alternator in the form of double walls and pumping coolant through these walls. In some cases, engine coolant is used, and the coolant pump of the engine serves to exchange coolant between the radiator of the vehicle and the alternator housing. In other cases, lubricating oil is the coolant, and the engine pump that circulates lubricating oil through the engine is used for exchanging oil between the crankcase sump and the alternator housing, the oil cooler of the engine serving to dissipate heat produced by the alternator.
Instead of using the engine coolant pump for circulating coolant through the alternator housing, an auxiliary pump driven by the engine can be used. In either event, the indirect nature of the heat transfer process makes this approach inefficient.
Another expedient is to spray lubricating oil from the engine inside the alternator housing into direct contact with the rotor and stator of the alternator. This approach extracts heat more efficiently inasmuch as a direct type of heat transfer is involved, but requires another pump to scavenge oil from the housing thus complicating the installation, operation, and maintenance of the alternator.
It is therefore an object of the present invention to provide a new and improved method of and means for cooling an alternator which overcomes many of the deficiencies of the prior art.